package NetEase;

import java.util.Scanner;

public class Main_0904_2 {
    public static void main(String[] args) {
        Scanner cin=new Scanner(System.in);
        int n=cin.nextInt(),k=cin.nextInt(),t=cin.nextInt();
        if (n-(k-1-t)<k){
            System.out.println("-1");
            return;
        }
        StringBuffer sb=new StringBuffer();
        if (k==n){
            for (int i = 0; i < n; i++) {
                sb.append("1");
            }
            System.out.println(sb.toString());
            return;
        }
        if (k==0){
            for (int i = 0; i < n; i++) {
                sb.append("0");
            }
            System.out.println(sb.toString());
            return;
        }
        sb.append("1");
        k--;n--;
        for (int i = 0; i < t; i++) {
            sb.append('1');
            k--;
            n--;
        }
        if (n<2*k){
            System.out.println("-1");
            return;
        }
        for (int i = 0; i < k; i++) {
            sb.append("01");
            n-=2;
        }
        for (int i = 0; i < n; i++) {
            sb.append("0");
        }
        System.out.println(sb.toString());
    }

/*    static int n,k,t;
    static String res="-1";
    //回溯
    public static void backtrack(int index,int count_one,int count_double_one,String path){
        if(index==n&&count_one==0&&count_double_one==0){
            //找到答案；
            res=path;
            return;
        }
        if (!res.equals("-1")||index>=n||count_double_one<0||count_one<0) return;
        //选择是0，还是1
        if (index-1>=0&&path.charAt(index-1)=='1'){
            backtrack(index+1,count_one-1,count_double_one-1,path+'1');
        }else {
            backtrack(index+1,count_one-1,count_double_one,path+'1');
        }
        backtrack(index+1,count_one,count_double_one,path+'0');
    }
    public static void main(String[] args) {
        Scanner cin=new Scanner(System.in);
        n=cin.nextInt();
        k=cin.nextInt();
        t=cin.nextInt();
        if (k>n||t>=k) {
            System.out.println(res);
            return;
        }
        if (k==n&&t-1==k){
            StringBuffer sb=new StringBuffer();
            for (int i = 0; i < n; i++) {
                sb.append("1");
            }
            System.out.println(sb.toString());
            return;
        }
        backtrack(0,k,t,"");
        System.out.println(res);
    }*/
}
